Answer:
21/50
Step-by-step explanation:
The given expression can be evaluated as follows.
[tex]\left(\dfrac{2}{10}+\dfrac{4}{10}\right)-\left(\dfrac{6}{10}\times\dfrac{3}{10}\right)\\\\=\dfrac{2+4}{10}-\dfrac{6\times3}{10\times10}=\dfrac{6}{10}-\dfrac{18}{100}\\\\=\dfrac{30}{50}-\dfrac{9}{50}=\boxed{\dfrac{21}{50}}[/tex]
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Additional comment
We reduced the fraction 18/100 to 9/50 before looking for a common denominator with 6/10. The common denominator turned out to be 50, so the 6/10 fraction became (6/10)(5/5) = 30/50.